This invention relates to reflectors, specifically, to reflectors in the cross-sectional shape of conic sections for fluorescent light fixtures. Other patents have taught how to use reflectors on light fixtures which have a cross-sectional shape generally hyperbolic, generally elliptic, or generally parabolic. For example, U.S. Pat. No. 4,089,047 uses reflectors with elliptical cross-sections with the feature of one set of focuses of the ellipses being coincident and with the other focuses located at the ceiling level. These incandescent light fixtures use only reflected light with the embodiment designed such that all direct light coming from the light source is blocked. This patent would restrict the fixture to something small in diameter in order to meet the requirement of having one set of focuses coincident. Having all direct light blocked seriously limits the efficiency and usefulness of the lamp. A hyperbolic reflection surface is added to the lamp in another embodiment which is described, however, no diagram of the configuration is provided and the juxtaposition of the light source and the focus of the hyperbola is not taught.
U.S. Pat. No. 4,683,526 claims a desk lamp with a reflector in the shape of a parabola formed from a series of triangular facets. This patent claims a method to approximately construct at reasonable cost, a curved reflection surface to improve the light delivery from the lamp.
Although there are a number of fluorescent light fixtures on the market, few seem to utilize the direct light and reflected light coming from the light source to full advantage. Reflection surfaces are painted milky white which has a medium reflectance. Some reflectors are being made on special order to retrofit existing light fixtures, reduce the number of fluorescent tubes, and thus improve the light efficiency and energy utilization. These retrofit reflectors are fabricated by bending them into rectangular facets thus approximating a parabola in cross-sectional shape. A highly reflective material, such as Silverlux by 3M Company, applied to the surface of a thin aluminum sheet, is being used on these reflectors.
Generally, fluorescent light fixtures which are designed to provide illumination for an area should:
a. Uniformly illuminate the area. PA1 b. Minimize the formation of shadows. PA1 c. Provide light agreeable for human activity. PA1 d. Minimize the use of energy while providing an adequate level of illumination.
Accordingly, there is a need for new, optimized, light fixtures which will provide uniform light patterns coupled with an adequate level of illumination, and providing substantial energy savings. They must be suitable for use in new building construction or retrofit to existing structures, for illumination of art works or advertising signs, and for use in homes, stores, and offices.